Certain known high frequency counting circuits utilize Schmitt trigger circuits for toggling following counter stages in response to each event of the applied signal level crossing selected reference signal levels. One difficulty encountered with trigger circuits of this type which use contemporary components is that reliable triggering operation is impaired at the upper frequency limit of the Schmitt trigger circuit. In addition, recurring gating signals and associated counteroperating signals in conventional counters make it difficult to determine the frequency of signals appearing in bursts.